Category: marine and aquatic life

Life found deep beneath an Antarctic ice shelf

February 16, 2021 • 12:15 pm

There are two places on Earth that constitute Vast Unknowns with the potential for finding new species. One, the tropical rain forest, is relatively easy to access, but the area is so vast and difficult of access that there is much to be discovered. And of course the tree canopies, which are rich with life, are not so easy to access.

The other place is the deep sea, particularly around and below the Antarctic continent. A new paper from Frontiers in Marine Science (click on screenshot below, pdf here, full reference at bottom), describes a batch of organisms, some with stalks, clinging to a rock beneath an ice shelf attached to the land.  The interesting part of this study is not only the existence of life deep below ice shelves (that’s been seen before, including observations of fish, worms, anemones and mollusks), but life so far away from the open sea.  What the eight researchers found was a group of stalked and nonstalked sessile organisms, probably sponges, clinging to a small boulder resting on the sea floor. The boulder was 260 km (160 miles) in from the edge of the Ronne Ice Shelf. (A shorter piece in the Guardian is here.)

This means not only are there sessile, filter-feeding organisms living far away from where the food comes from, but, even more striking, the currents that could bring detritus and microorganisms to those sponges are not from the closest open ocean, but from the opposite direction, since that’s where the currents come from. Given these currents, food for the observed species probably comes from between 625 and 1500 km (388-932 miles) away: the nearest open ocean that constitutes the source of photosynthesis that ultimately yields all the food.  The researchers couldn’t collect the species, for they can be observed only through small holes bored with hot water through the thick shelf. Further, the big rock to which the organisms were affixed is 1233 m (4045 feet) below the ice. Given their remoteness, it’s almost certain that these species are new to science.

What’s striking about all this is that the total area explored by many researchers under the vast Antarctic ice shelves, which are so hard to penetrate, is smaller than a tennis court!  Imagine what’s under there! This, however, is the first time that any sessile (immobile) organisms have been found on a substrate below an ice shelf. The remaining organisms involved—and there’s a table of them in the paper—are mobile (i.e., fish) or live on a soft, sea-bottom substrate.

Click to read the paper; I’ve put some videos of what they saw in the tweets below.

Here are the two great Antarctic ice shelves: the Ross and the Ronne (11 o’clock at the top), with the map taken from the paper. The places where the shelves have been penetrated by boring are indicated with dots: filled black dots show sites that yielded observations of organisms, while the sites showing no life have open (white) circles. The one spot below the Ronne shelf that produced the sessile and stalked organisms in this study is marked with a yellow star.

The animals, which are likely to be sponges but could be some other sessile or stalked organisms like ascidians, barnacles, or even worms or cnidarians, were affixed to a “drop boulder” about 1 x 0.75 meters across. How did it get there? The term “drop boulder” is a clue: this was probably a rock from the mountains on the continent itself that found its way into glacial ice, and then moved onto the ice shelf. At some point it fell through the ice and onto the sea floor. It then—only Ceiling Cat knows how—got colonized from another site.

Here’s the figure from the paper showing the boulder and its affixed organisms. They’re not very clear, and they’ve had to outline and highlight the organisms. I’ve added the caption from the paper

Dimensions and close-ups of the boulder, highlighting where life is clearly visible (A–E) and the top of the boulder where no obvious life is visible (F). The taxa visible on the boulder: Red, large stalked sponge; White, sponge; Orange, stalked taxa [possible sponge, ascidians, hydroid, barnacles, cnidaria (e.g., tubularia), and polychetes].
Here are two videos, the first showing one of the scientists involved in the study explaining the find and its significance. The second video shows the organisms:  the blobs on stocks are particularly clear. You can see the difficulties of trying to manipulate a probe and a light in the darkness through a borehole more than 4,000 feet above. But yes, those aren’t artifacts: they’re alive!

Another map shows the holes drilled in the immediate area and the direction of the sub-shelf currents in the vicinity. The hole that yielded the view of the boulder is FSW2.  The black and purple arrows (see caption) indicate the direction of water flow, i.e., where the food comes from. As you see, the currents don’t flow from the nearest edge of the ice shelf but from a far greater distance, so the food particles have taken a circuitous route.

Map showing location of drill sites on Filchner Ice Shelf (FSW1-2, FSE1-2, and FNE2), comparable samples from continental shelf collected during JR275 as well as the major sub-ice shelf circulation. Black arrows show flows derived from High Salinity Shelf Water (HSSW) from the Ronne Depression. Purple arrow shows the flow from HSSW formed over Berkner Bank (Nicholls, 2004). Ice Shelf Water (ISW) exits along the eastern margin of Filchner Trough, with a possible seasonal influx of modified Warm Deep Water (mWDW) (Darelius et al., 2016). Dashed light blue arrows represent the flow of the slope front and coastal currents (Nicholls et al., 2009). Bathymetry is derived from ETOPO1 (NOAA National Geophysical Data Center, 2009).

The upshot: This is only a preliminary observation, and we don’t even know what those bloody creatures hanging onto the boulder are. But even observing them is a hard job: you have to get yourself onto the ice shelf with all your gear (perhaps they flew in), and then use a hot-water boring system to get through the thick shelf ice and then go down nearly a mile. To find out what these species are, they’d have to collect them, and that would involve either devising a boring/collecting device, or getting some kind of submersible below the shelf, most likely from above, which itself is nearly impossible. Going in below the shelf from the sea is theoretically possible, but it’s a big distance!

At any rate, what we know is that there are certainly many unknown species beneath the shelf, and maybe even unknown phyla. And once again we get the lesson that life is extremely tough and tenacious, here living in total darkness in near-freezing waters about a mile down, in an area where food is pretty damn scarce.

h/t: Jez

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Griffiths, H. J., P. Anker, K. Linse, J. Maxwell, A. L. Post, C. Stevens, S. Tulaczyk, and J. A. Smith. 2021. Breaking all the rules: The first recorded hard substrate sessile benthic community far beneath an antarctic ice shelf. Frontiers in Marine Science 8.

Aquanauts lived in an underwater marine lab for a month

March 16, 2020 • 2:00 pm

Here’s a fascinating 4.5-minute NOVA video about “aquanauts” who lived underwater as part of “Mission 31“, a project that has its own Wikipedia page. The endeavor took place from June 1 to July 2, 2014, with three members of the six-person crew replaced halfway through the endeavor.  The decompression at the end took 14 hours. It wasn’t just a stunt: 10 scientific papers came from this month of research.

The description of the lab from Wikipedia:

Jacques Cousteau’s grandson, Fabien Cousteau, organized Mission 31 as a tribute to his late grandfather. The mission had two goals — to gather scientific data and to raise funds for Aquarius, an underwater laboratory located at a depth of 63 feet (19 m) below the surface, about 9 miles (14 km) south of Key Largo. Aquarius is the world’s only operating undersea laboratory. Measuring 43 feet (13 m) by 9 feet (2.7 m), it holds up to six people. It is pressurized, air conditioned, and has wireless Internet access. A typical mission lasts 10 days, with the longest previous mission lasting 18 days. Aquarius is owned by the United States government’s National Oceanic and Atmospheric Administration and run by Florida International University.

Fabien Cousteau also hoped to break his grandfather’s record for longest time spent underwater by a film crew, and draw the public’s attention to environmental issues. According to Guinness World Records, the longest time anyone has spent underwater is 69 days.

Readers’ wildlife photos

December 19, 2019 • 8:00 am

Today we have the second and last batch of Joe Dickinson’s photos from Peru (the first batch is here). Joe’s notes and IDs are indented.

I continue with more monkey business.  Same species (and individuals) as at the end of the previous post.

The wooly monkey (genus Lagothrix):

I include this shot just to show how close we were able to get.  We were in one of the small skiffs used for side trips from the main river boat.

Spider monkey (genus Ateles):

I believe this is a grey throated (or dark throated) hawk, but I can’t find anything more specific.  They were quite common.

Not strictly wildlife (or a great photo), but we visited a manatee rescue center where we were able to see that rare animal (Trichechus inunguis).  You can see the horizontally flattened paddle-like tail.  As with whale flukes, this clearly is used in vertical propulsion strokes rather than side to side like fish. This reflects the fact that aquatic mammals are derived from land mammals that flexed the spine up and down when running.

Also not really wild, guinea pigs (Cavia porcellus) are raised as food.  Some in our group gave it a try, but I can’t get past a passage in a travel memoir that I read years ago describing a guinea pig roasted whole as looking like “the victim of a forest fire”.

This chinchilla  (Chinchilla lanigera, I think) was living in a somewhat lower class ancient Inca house (judging from the rather crudely fitted stonework compared to the extraordinary work on things like temples and some higher class houses).

Also probably not wild, these alpacas (Vicugna pacos) were wandering free near one of the Inca sites we visited.

And this alpaca clearly is not wild, but very cute.

And a llama (Lama glama), wild or domestic I don’t know, wandered by in time to give me an excuse for including Machu Picchu in a set of purported wildlife photos.

And another “ringer” just because I really like this photo.  This is at Otavalo, Ecuador, photographed during a post trip excursion connected to a visit to the Galapagos a few years ago.

A woman who hugs sharks

March 29, 2019 • 3:00 pm

Reader Michael found this short video of a woman who likes to pet and hug Caribbean reef sharks (Carcharhinus perezi). As the YouTube video notes say, “Cristina Zenato is the woman who isn’t afraid to hug sharks.”

If you’re wondering how dangerous this shark is, the answer is “not much.” Wikipedia says this:

Normally shy or indifferent to the presence of divers, the Caribbean reef shark has been known to become aggressive in the presence of food and grows sufficiently large to be considered potentially dangerous. As of 2008, the International Shark Attack File lists 27 attacks attributable to this species, 4 of them unprovoked, and none fatal.

Readers’ wildlife photos

March 23, 2019 • 7:45 am

I suspect this will be the last installment here for about two weeks, but if you’ve sent in photos, never fear: I have them all here in Chicago. Today’s contribution is from Joe Dickinson, whose notes are indented:

Not technically “wildlife”, nevertheless here are some photos from the Monterey Bay Aquarium. The first two are jellyfish.  I’m afraid I don’t know even the common names let alone the scientific binomials.

This handsome fellow (or gal) is an African penguin (Spheniscus demersus).

Here is a moray eel, perhaps Gymnothorax reticularis, being serviced by cleaner shrimp, probably Lysmata amboinensis.

These are clownfish (Amphiprion ocellaris?) with an unknown species of anemone.

These next two are sort of out of their element in an aquarium.  Nevertheless, here they are.  The first is a common chuckwalla (Sauromalus ater) and the other is a desert tortoise (probably Gopherus agassizii )

 

These are aptly named garden eels (genus Heteroconger).

This stone scorpionfish I could only ID down to family (Scorpaenidae).

The lookdown (Selene vomer) also is very aptly named.

Readers’ wildlife photos (and videos)

March 6, 2019 • 7:30 am

We’re running a bit low on photos, at least sufficiently low that I’m getting nervous. I may have to suspend this feature in a week or so unless we get some good readers’ photos.  If you have ’em, please send ’em. And remember to give the Latin binomial and to try to limit each submission to ten picture. Thanks!

Today we have some nice underwater photos (and videos given in links) from reader Peter Klaver, whose words are indented:

Here are some pictures and links to video from scuba diving trips we had in the Red Sea and Gulf of Aqaba (at times when the Sinai peninsula was less dangerous to go to than it has been for much of the time since then).
Here is a third batch from diving trips in Egypt. We saw bluespotted ribbontail rays, Taeniura lymma, on several occasions.

Sometimes they cover themselves with sand a bit.

But we saw them swimming too, like in the video here.
In addition to hard corals, giant clams, Tridacna gigas, grow there too. If you come near them they can sense that and they will sometimes close up, as you can see in the video here. I estimate the one in the picture below was ~30 cm long.

Crocodile fish, Papilloculiceps longiceps, blend in well with the bottom.

Box fish (no idea which one this is, or its Latin name) on the other hand stand out clearly.

I think this pufferfish is Arothron stellatus.

Moray eels are a common site but mostly just their heads sticking out of rock openings. But we did see one out and about, see video clip here.

And finally, we did our diving from liveaboard boats. At one point we had dolphins (Delphinus capensis or Delphinus delphis?) playing around our vessel.

The bizarre anglerfish: first video of their equally bizarre mating

March 22, 2018 • 11:30 am

You’ve surely heard of the bizarre anglerfish. There are actually many such species in the order Lophiiformes, but the most famous are the deep-sea species with fearsome teeth who attract their prey with a luminescent lure. (All anglerfish are carnivorous.) Here’s a picture of ten such species from Wikipedia:

Their huge mouths and distendable stomachs enable them to eat prey twice their size: a useful adaptation in the deep sea, where prey are few and far between. And the reproduction of some species, as shown in the stunning video below, is totally bizarre (see this Mental Floss piece for more information). Males are tiny, and weren’t even known to exist until many females had been caught, many afflicted with “parasites”. Scientists eventually realized that the parasites were actually males whose bodies had become permanently fused to the female. That’s a good mating strategy because finding a female in such sparse populations is a real problem. But it’s almost unique in animals.

When males are born, they have to find a female, and they do so by homing onto her using both her light and species-specific pheromones. Such males can’t feed, and don’t get mature gonads until they attach to a female. When a male does that, he secretes an enzyme that dissolves his head and the female’s body wall, allowing the pair to fuse right down to joining their blood vessels. The male remains attached to the female for life, and can spawn repeatedly until she dies (how the male releases sperm when the female produces eggs is something I haven’t yet found out). As I used to tell my students, to their great delight, “the male anglerfish is simply a parasitic sack of gonads—much like undergraduate men.”

A piece in Science by Katie Langin describes the filming of the first pair of mating anglerfish, made at 800 meters near the Azores by Kirsten and Joachim Jakobsen in a submersible (shown in the video below). They followed the 16-cm animal (about six inches long: the size of an American dollar bill) for 25 minutes, and later identified the species as Caulophryne jordani, or the “fanfin angler”, which has a worldwide distribution.

The short video below, put out by the AAAS, shows several interesting features:

  • The long whiskers of the females of this species, which likely act as feelers. These structures appear to glow like the bioluminiscent “lure,” but the researchers aren’t sure whether the glow of the whiskers is intrinsic or merely reflections from the submersible.
  • The male seems to move his body about independent of the female
  • The female uses little energy swimming, and appears to mostly drift around. That’s probably an energy-saving adaptation in a food-poor environment. After all, why swim when you have nowhere to go, and when your prey comes to you?

Have a gander of one of the world’s truly bizarre creatures, and one of the marvels of natural selection.

h/t: Matthew Cobb